Vessels are commonly treated to reduce or eliminate narrowings caused by arteriosclerotic disease. Interventional treatments can include use of balloon angioplasty, stenting, thrombectomy, atherectomy, and other procedures. During treatment particulate debris can be generated at the treatment site. Infarcts, strokes, and other major or minor adverse events are caused when debris embolizes into vasculature from the treatment site.
To prevent embolization of debris, embolic protection devices have been developed. Embolic protection devices can remove emboli from the bloodstream by filtering debris from blood, or by occluding blood flow followed by aspiration of debris, or by causing blood flow reversal to effect removal of debris. The shape, length and other characteristics of an embolic protection device are typically chosen based on the anatomical characteristics in the vicinity of the treatment site. However, some anatomies present specific challenges due to the anatomical shape or configuration.
One type of embolic protection device is introduced into a vessel on one side of a treatment site, such as upstream from a lesion, and positioned on the other side of the treatment site, such as downstream from a lesion. Such embolic protection devices must traverse or cross the treatment site in order to be deployed in the vessel and thereby protect the patient from the effects of embolic debris. Some embolic protection devices are designed as fixed wire systems in which several components, such as a filter, a wire, and a sheath cross the treatment site in unison. However, due to the bulk of the several components not all lesions can be crossed by fixed wire embolic protection systems. Other embolic protection devices are designed to be used with wires of choice. In wire of choice systems a standard guidewire of the physician's choosing is first advanced alone across a treatment site, followed by advancement of other components, such as a filter and a sheath, over the guidewire and across the treatment site. In some cases the guidewire of choice will then be removed from the vicinity of the treatment site. While wire of choice systems are nearly 100% successful in crossing treatment sites such as lesions, they are more time consuming to use than fixed wire systems due to the added number of steps needed for initially crossing with the wire of choice and subsequently crossing with additional components.
In some anatomies fixed wire systems can be expected to cross the majority of treatment sites. Unfortunately, it is not always possible to predict which treatment sites are crossable with a fixed wire system and which treatment sites will require crossing by a wire of choice approach. If the fixed wire system cannot cross the treatment site then the system must be withdrawn and an alternate approach such as a wire of choice system must be utilized instead, increasing procedural time, complexity, and expense.
What is needed in the art is an embolic protection device that can be initially used as a fixed wire system and easily converted into a wire of choice system should the need arise.